Communications review

The more things change the more they stay the same — except in marine communications, that is. Change has been running rampant through the industry in the last six years, and sailors have more choice than ever before when it comes to finding a reasonably priced solution for keeping in touch while they’re out at sea.

I had the opportunity to try out several different communications platforms on a trans-Atlantic passage in the fall of 2002. For the most part, they all worked as advertised, and where they didn’t, the technical support offered was responsive and reliable. For more details about the trip and the devices I used, see Ocean Navigator’s email newsletters — or better yet, sign up for the free newsletters at

Let’s consider the available devices in the following categories:

Satellite data-only systems

The granddaddy of satellite email is Inmarsat-C. Third in a line of satellite systems with alphabetic names, Inmarsat-C (sometimes referred to as sat-C or standard-C) offers a very simple text-only email system to ocean voyagers in all oceans between 70° N and 70° S. One of its key advantages is a push-the-red-button type of distress feature that sends an encoded message — including the vessel’s identity, position, course and speed — to the nearest rescue center. It’s also the delivery mechanism for SafetyNet — a worldwide navigation and weather warning system that provides text forecasts and navigational warnings to all vessels in a certain area. This is how we first learned of the Prestige disaster — a tanker that sank in waters not too far away from where we were sailing on our trans-Atlantic trip.

Inmarsat-C is priced per character rather than per minute. This means an email of a certain size is sent for a fixed price, no matter how much airtime is involved in sending the message.

SkyMate (formerly Boater’s MiniWeb, is a relative newcomer to the marine communications field, but it makes use of mature technology that’s been around for many years. For well under $1,000, you can purchase the SkyMate black-box email system (actually a silver box), which connects to your computer and a VHF-style whip antenna. Hook it up to 12-volt DC power and (optionally) your GPS, and that’s all you need. There are no buttons or dials on the box, simply a few LEDs to indicate that the system is operating properly and notify you of waiting inbound email.

SkyMate is a store-and-forward system that charges by the character rather than by the minute. Like Inmarsat-C, this means that an email of a certain size will be sent for a fixed cost, no matter how long it takes to transmit the message over the airwaves. In addition to regular text-only emails, SkyMate offers users the ability to send faxes and even voicemail to people over the phone — your outgoing message is read by a computerized voice and delivered to a phone number you choose. This was very entertaining for the crew on a recent passage, as we each took turns leaving messages on the answering machines of our spouses and families at home.

SkyMate is a handy alternative to Inmarsat-C, but be aware that it does not have distress and safety functionality. It does have an easy-to-use interface to allow you to pull down weather on demand, but there’s no big red distress button and no SafetyNet messages.

The last item in the satellite data-only category is a vastly different product. The TracNet system from KVH ( allows boats to maintain high-speed Internet connectivity while at sea (and at the dock). TracNet uses digital television satellites to beam down Internet data at up to 400 kbps (kilobits per second) — for comparison purposes, this falls somewhere between a home DSL connection and a cable Internet connection. Certainly faster than just about any other bluewater Internet connection available. It’s not a cheap system (see the complete chart online at, but for those whose needs demand it, it fits the bill nicely. Though downloading information over TracNet is blazingly fast, be aware that information flowing in the other direction does so over limited speeds. This isn’t a problem in most cases — browsing the Web, retrieving emails and obtaining weather forecasts require information to flow largely in one direction (from the Internet to the boat). However, when it comes time to send home a digital photo of the sunset, be prepared to wait a little while (or compress the photo down to a manageable size).

HF/SSB data-only systems

High-frequency radios have long been a staple of the offshore marine communications toolbox. HF transmissions can easily travel several hundred miles and sometimes several thousand miles. Within the HF range of radio spectrum are two separate and distinct sets of frequencies — one set is allocated to licensed amateur (ham) operators only, while the other set of frequencies is allocated specifically for marine use. Once a frequency is decided upon, a mode needs to be selected — this relates to how the information will be sent over the airwaves: Will it be sent by Morse code? By voice? For all marine frequencies, transmissions are always made in single-sideband mode. For this reason, marine HF radios are often referred to as SSB radios.

Since the email boom in the mid-1990s, companies have stepped up their efforts to make email over HF an affordable and efficient method of communication. A critical component in being able to send email from a computer through an HF radio is an HF modem. While there are a few different types available, nearly every boat with an HF modem has one of the PTC-II series from Special Communications Systems in Germany. These PTC-II modems are the only ones that can make use of SCS’s advanced Pactor II and Pactor III protocols for squeezing lots of data through a relatively small chunk of airwaves.

The industry that has sprung up around HF email has seen tremendous change in the past couple of years. One of the earliest surviving HF email service providers is SailMail ( Technically, SailMail is a non-profit association of members who each contribute $200 to keep the system running. In return for this $200 annual fee, members are allotted up to 10 minutes each day during which they can use their computer, SSB radio and Pactor modem to send and receive email. Due to the immense popularity of SailMail, it may be difficult to find an available frequency during high usage — this will probably be most noticeable during mass migrations of boats, such as Bermuda races or ocean rallies. However, with 13 locations around the world, a little patience and dexterity with your tuning knob, you can usually find an available station. If your needs are such that you regularly exceed the 10-minute daily allotment, you’ll be asked politely to switch to another provider.

Two fairly new Florida-based companies are each taking the SailMail concept and ramping it up a notch by adding more features and capabilities, and operating as for-profit ventures. Pompano Beach-based CruiseEmail (, founded by Dr. John Gregory, has cooperating station locations in Florida, Maryland, Grenada and Belize, covering the east coast and Caribbean cruising grounds quite well. Plans exist to bring two stations in the Mediterranean online soon.

Jupiter, Fla.-based MarineNet Wireless (, founded by amateur radio operator John Heron, is replete with bells and whistles. Most notable among them is the email software that’s optimized for use over slow-speed connections. In addition to automatically compressing email messages, it allows the user to view a message and delay downloading large attachments until a fast connection is available (typically onshore). This feature alone can save quite a bit of money when someone accidentally emails you a large photograph attached to an email without realizing that it might cost you upwards of $50 just to download it! MarineNet maintains cooperating station locations in Florida, Germany and Michigan, and the company plans for more stations to come online.

The largest and most well-funded of the HF email service providers covered here is Middletown, R.I.-based SeaWave ( With their eyes on the lucrative commercial maritime market, SeaWave’s innovative technologies are trickling happily down to the recreational market. Their current version-two service is based on their Navigator software, which contains the ability to download attachments selectively, and offers fixed-price weather downloads at $0.95 to $1.95 each. In addition, SeaWave seems to be pioneering the commercial rollout of the concept of automatic link establishment, which essentially tunes your radio to the best available station automatically, without requiring any user input. This is welcome news for anyone intimidated by radio-signal propagation tables.

For boaters who have passed the (relatively easy) test to operate on amateur frequencies and are in possession of their ham license, the Win Link ( service offers free email with a station network of more than 30 locations. No, that’s not a typo — the email is completely free. The only catch is that you can’t conduct business-related communications over amateur frequencies. And being a volunteer service, there’s no central technical support center to call in the event of any complications with your setup.

For continuing updates on HF email service providers, see the comparison chart maintained by Tim Hasson of Marine Computer Systems Inc. and offered for free at

Satellite voice/data systems

The most popular systems found on many oceangoing boats are those offering both data/email capability and the ability to place a phone call back home from the middle of the ocean. The forefather of satellite-based marine communications is Inmarsat ( Originally a consortium of maritime countries interested in providing reliable communications for safety, Inmarsat was privatized in 1999 but still focuses heavily on the marine markets. Their first product small enough for the average yacht was Inmarsat’s mini-M telephone — modern versions consist of a belowdecks telephone unit and an abovedecks antenna dome, typically measuring less than 10 inches in diameter. In addition to placing and receiving telephone and fax calls, the mini-M is capable of transmitting emails at the rate of 2,400 bps. By comparison, a dial-up Internet connection operates at about 56,000 bps. As with nearly all other competing products, mini-M’s speed is too slow to surf around the Web, but it is adequate for most text-based email messages and the odd attachment or two.

Relative newcomers, Iridium ( and Globalstar (, use satellites in a much lower orbit than those of Inmarsat. This allows the hand-held telephone units to have enough transmitting power to reach the satellite without needing either a stabilized, directional dish antenna or an overly large battery pack. Both companies have seen their fair share of financial troubles, with Iridium entering and re-emerging from bankruptcy and Globalstar currently working on a plan to emerge from bankruptcy.

Globalstar offers crystal-clear voice quality and a data speed of 9,600 bps, while archival Iridium operates at only 2,400 bps (the same speed as mini-M). Globalstar’s coverage is extensive, but not entirely global (see coverage map at On the other hand, Iridium’s truly global coverage is one reason the U.S. Department of Defense just renewed its multi-year contract with Iridium.

About this time last year, Inmarsat upped the stakes of offshore data communications by launching its Fleet F77 service. Though the 3-foot-wide antenna and the $24,000 price tag put the system out of reach for most recreational voyagers, the two significant technological advances of Fleet F77 are its fast 64,000-bps data speed and its ability to maintain an always-on connection, in which the user is charged according to the quantity of data transmitted as opposed to the length of time connected — the difference between the digital approach of billing by the byte and the telephone model of billing by the minutes a circuit is open.

Of more interest to the sailing market is the pending launch of Fleet F55 and the subsequent launch of Fleet F33. The Fleet F55 system will be lighter, smaller and cheaper than Fleet F77. It will maintain the high speed of the larger system but won’t be approved for the Global Maritime Distress and Safety System. Fleet F33 will sport an antenna about a foot in diameter and will offer speeds up to 9,600 bps.

To keep up to date with the latest developments in satcom options, see the author’s free satellite communication comparison chart at

Dan Piltch, founder of Marine Computer Systems Inc., studies the marine technology industries and translates their offerings into practical advice for his clients.

By Ocean Navigator